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<h1><img style="width: 32px; height: 32px;" src="images/ico.gif" alt="" hspace="15" vspace="5"> &nbsp;<span style="text-decoration: underline;">DEM - Digital Elevation Model</span></h1>
<h1><img style="width: 493px; height: 361px; float: right;" src="images/dialog.png" alt="" hspace="30"></h1>


DEM is tool which provides some 3D spatial operations:<br>
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  <li><span style="font-weight: bold;">creating TIN (Triangulated Iregullar Network)</span></li>


  <li>
    
    <span style="font-weight: bold;">creating izolines from TIN</span></li>


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<div style="margin-left: 40px;"><big><span style="font-weight: bold;">1. TIN<br>
<small>1.1 Source</small></span></big></div>
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<div style="text-align: left; margin-left: 40px;">At first you must create TIN. At the left side of toolbox you must choose source<span style="font-weight: bold;"> <span style="font-style: italic;">points layer</span></span>. TIN will be counted in 2D from geometry (X,Y<span style="font-style: italic;"> coordinates</span>) of shapefile. Coordinate Z you must choose from attribute table of the same shapefile. This is cell <span style="font-weight: bold;"><span style="font-style: italic;">height source.&nbsp; </span></span><big><span style="font-weight: bold;"><br>
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1.2 Break Lines<br>
</span>At this part you may set layer of break lines. <span style="font-weight: bold; font-style: italic;">Hard break lines </span>are lines, where the surface will have sharp break. <span style="font-style: italic;"><span style="font-weight: bold;">Soft break lines </span></span>are lines, where surface will have soft break as crest line. <br>
Attention: input layer of break lines has to contains lines which have
same points as the source points layer. If the input break line doesn't
contain same points, it will not be counted to final TIN.<br>
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If you have selected sources, you may use button <span style="font-weight: bold; font-style: italic;">Count TIN </span>and new TIN will be add as a new temporary layer.&nbsp;If you want to save it as shapefile, you must export it.<br>
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<big><span style="font-weight: bold;">2. Surface creator</span></big><big><small><big><big><small><small><img style="width: 350px; height: 202px; float: right;" alt="curvedTriangles" src="images/curvedpntriangles.png" hspace="100"></small></small></big></big></small></big><br>
<big><span style="font-weight: bold;"><small>2.1 Izolines<br>
<big><big><span style="font-weight: bold;"></span></big></big></small></span><small><big><big><small><small>When
you have comlpleted TIN, you may count izolines. At first you must set
a level of dividing triangles as you can see at the picture. Number of
triangles determines&nbsp; level of smoothing surface. Be carefull,
because when you set high level, the data structure will be
monstrous.&nbsp;&nbsp; <br>
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<span style="font-weight: bold;">2.2 Set elevated difference</span><br>
Last step of exctracting izolines is setting of elevated difference
between izolines. Unit is same as weight source. Standart value for it
is 10.<br>
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</small></small></big></big></small></big>If you have all selected, you may use button <span style="font-weight: bold; font-style: italic;">Count Izolines </span>and new izolines will be add as a new temporary layer.&nbsp;If you want to save it as shapefile, you must export it.<br>
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have a nice work :)<br>
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